Question error message.....with unity jobs

hello
i have this message

Library\PackageCache\com.unity.jobs@0.8.0-preview.23\Unity.Jobs\IJobParallelForDefer.cs(77,85): error CS8377: The type 'U' must be a non-nullable value type, along with all fields at any level of nesting, in order to use it as parameter 'T' in the generic type or method 'NativeList<T>'


what should I actually do?
I have to go back to the old lts version or is there a way to clean up unity?

 

I would guess that these would be good avenues to investigate further:

- a package you are using isn't compatible with the version of Unity you have

- a package you are using isn't compatible with another package

- there might be a mistake in the package requirements data

If you don't need a package, remove it.

Extra unwanted packages in new projects (collab, testing, rider and other junk):

https://forum.unity.com/threads/temp-unityengine-testrunner-dll-error.1133938/#post-7287748

About the fastest way I have found to make a project and avoid all this noise is to create the project, then as soon as you see the files appear, FORCE-STOP (hard-kill) Unity (with the Activity Manager or Task Manager), then go hand-edit the Packages/manifest.json file as outlined in the above post, then reopen Unity.

Sometimes the package system gets borked from all this unnecessary churn and requires the package cache to be cleared:

https://stackoverflow.com/questions/53145919/unity3d-package-cache-errors/69779122

 

ok
but if the unity manages to detect that a file is not compatible with the version used, why does it not automatically clean it or specify which file is inconsistent. or notify before installation....

how do artists who are not developers do ?

 

Packages usually depend on other pacakges, and they will automatically install the required version. But if you manually install other versions, there’s nothing the package manager can do.

Doesn’t really take a programmer to figure out and fix these kind of things, just make sure that you’ve installed verified versions of the packages and that they work ok with each other.